In 2016 I submitted a C# proposal for Buildable Immutable Types to the Roslyn team. The feedback I got from other community members was that my proposal would work better as a T4 Template or as part of the "upcoming Source Generation" feature.

Now, 4 years later, with Source Generators finally coming to C# I thought it would be the right time to follow up on it.

Previously we discovered how to hold an unboxed instance of System.Void, and although circumventing the .NET framework always feels good, it left us with a burning question; What does the memory layout look like? Can a class contain infinite voids?

Previously we have show how we can obtain an instance of System.Void, despite some effort by the .NET team to disallow that. However the API we used returned an object which led to the boxing of the void instance. Having a box of nothing is not the same as having nothing, so it seems like we must take an alternative route so that we can finally hold an unboxed void.